Wind Energy/Transcript
Transcript Text reads: The Mysteries of Life with Tim and Moby Tim and Moby are walking outside on a rainy, windy day. Tim is holding an umbrella. Tim's umbrella breaks, then Tim and Moby go indoors. A letter floats in with the wind and Moby catches it. MOBY: Beep. Tim reads from the typed letter. TIM: Dear Tim and Moby, How is wind used to make energy? From, Annika. That's a good question. First, some history. An animation shows wind blowing a tree and a weather vane. TIM: It may seem strange to think of wind as a source of energy, but we've been harnessing it for thousands of years. An animation shows men in an ancient sailboat. TIM: In Ancient Egypt, people used wind to power their sailboats along the Nile River. An image shows the ancient country of Persia. TIM: The first windmills were used in Persia, in today's Middle East region, about fifteen-hundred years ago. An animation shows an ancient windmill spinning around. Next to it are a man and large bags of grain. TIM: Primitive windmills looked sort of like egg-beaters and were mainly used for grinding grain and drawing water from wells. An image shows two people in traditional Dutch garb next to a more modern, propeller-like windmill. TIM: Later, people in Western Europe improved on the technology by making propeller-style blades out of sails. An animation shows wind turbines in a field, and lights turning on in nearby buildings and in a streetlamp. TIM: Today, modern wind turbines are strong, sleek, and well-suited for converting the force of wind into energy. MOBY: Beep? An animation shows wind moving around the windmill's blades. TIM: Well, the rotor blades are aerodynamically shaped to make them really efficient. An animation shows the blades spinning. TIM: The blades convert the wind's energy into a rotational energy called torque. How much torque is produced depends on three things: air density, wind speed, and the length of the rotor blades. Images show the three things Tim describes. TIM: As each of these factors increases, so does the amount of power produced. When strong winds blow against a turbine, the force causes the rotors to turn pretty quickly. Inside the turbine, a generator converts the movement into electricity. That electricity can be sent through power lines to light up your house. An animation shows the process Tim describes of a turbine converting wind to electricity and lighting a house. MOBY: Beep. An animation shows wind turbines in a field. TIM: Actually, there are lots of places where you can see wind turbines at work, but one of the most dramatic is called a wind farm. MOBY: Beep. Moby covers his mouth and laughs. MOBY: Beep. TIM: No, they don't grow wind in a wind farm, but it's a place where electricity is made from wind. An animation shows a wind farm. TIM: Wind farms typically have at least a couple dozen turbines that are positioned to take advantage of local wind patterns. MOBY: Beep. TIM: Good point. Many people think it's a good idea to invest in renewable energy sources like wind, which is clean and relatively cheap to generate. Images show wind and sun. TIM: A renewable energy source is a source of energy that for all practical purposes never runs out, like wind or solar energy. That's in contrast to fossil fuels like coal and oil, which the earth only has finite amounts of. Images show coal and oil. TIM: Right now, only about one percent of all the power we use in America is created by wind. Even so, the United States is the second-highest producer of wind energy in the world. A map titled U.S. Average Wind Power shows that a large amount of the country is suitable for wind farms. TIM: And since North America has more sites suitable for wind farms than any other continent, our wind power output should have no problem growing. MOBY: Beep. TIM: Yeah, there are a few drawbacks to getting electricity from wind. An image shows a boy frowning at the sight of turbines outside his house. TIM: For one thing, some people think turbines are ugly, and they don't want to look at them all day. Other people worry that wind turbines are dangerous to flying animals, like birds and bats. An animation shows birds flying. TIM: Some studies suggest that the numbers of animals hurt by wind turbines is fairly small. But it is a real problem that the wind energy industry is looking into. Tim and Moby are outside on a very windy day. Moby opens an umbrella. MOBY: Beep. TIM: Naw! It's windy out here, but not that… Tim trails off as Moby flies straight up into the air, sailing higher and higher above his neighborhood. TIM: windy. Category:BrainPOP Transcripts